Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/js/src/util/DoubleToString.h b/js/src/util/DoubleToString.h
new file mode 100644
index 0000000000..06f433257f
--- /dev/null
+++ b/js/src/util/DoubleToString.h
@@ -0,0 +1,115 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef util_DoubleToString_h
+#define util_DoubleToString_h
+
+/*
+ * Public interface to portable double-precision floating point to string
+ * and back conversion package.
+ */
+
+#include <stddef.h>
+
+struct DtoaState;
+
+namespace js {
+
+extern DtoaState* NewDtoaState();
+
+extern void DestroyDtoaState(DtoaState* state);
+
+}  // namespace js
+
+/*
+ * js_strtod_harder() returns as a double-precision floating-point number the
+ * value represented by the character string pointed to by s00. The string is
+ * scanned up to the first unrecognized character.
+ *
+ * If se is not nullptr, *se receives a pointer to the character terminating
+ * the scan. If no number can be formed, *se receives a pointer to the first
+ * unparseable character in s00, and zero is returned.
+ *
+ * On overflow, this function returns infinity and does not indicate an error.
+ */
+double js_strtod_harder(DtoaState* state, const char* s00, char** se);
+
+/*
+ * Modes for converting floating-point numbers to strings.
+ *
+ * Some of the modes can round-trip; this means that if the number is converted
+ * to a string using one of these mode and then converted back to a number, the
+ * result will be identical to the original number (except that, due to ECMA, -0
+ * will get converted to +0).  These round-trip modes return the minimum number
+ * of significand digits that permit the round trip.
+ *
+ * Some of the modes take an integer parameter <precision>.
+ */
+/* NB: Keep this in sync with number_constants[]. */
+typedef enum JSDToStrMode {
+  DTOSTR_STANDARD, /* Either fixed or exponential format; round-trip */
+  DTOSTR_STANDARD_EXPONENTIAL, /* Always exponential format; round-trip */
+  DTOSTR_FIXED,       /* Round to <precision> digits after the decimal point;
+                         exponential if number is large */
+  DTOSTR_EXPONENTIAL, /* Always exponential format; <precision> significant
+                         digits */
+  DTOSTR_PRECISION    /* Either fixed or exponential format; <precision>
+                         significant digits */
+} JSDToStrMode;
+
+/* Maximum number of characters (including trailing null) that a DTOSTR_STANDARD
+ * or DTOSTR_STANDARD_EXPONENTIAL conversion can produce.  This maximum is
+ * reached for a number like -0.0000012345678901234567. */
+#define DTOSTR_STANDARD_BUFFER_SIZE 26
+
+/* Maximum number of characters (including trailing null) that one of the other
+ * conversions can produce.  This maximum is reached for TO_FIXED, which can
+ * generate up to 21 digits before the decimal point. */
+#define DTOSTR_VARIABLE_BUFFER_SIZE(precision)    \
+  ((precision) + 24 > DTOSTR_STANDARD_BUFFER_SIZE \
+       ? (precision) + 24                         \
+       : DTOSTR_STANDARD_BUFFER_SIZE)
+
+/*
+ * DO NOT USE THIS FUNCTION IF YOU CAN AVOID IT.  js::NumberToCString() is a
+ * better function to use.
+ *
+ * Convert dval according to the given mode and return a pointer to the
+ * resulting ASCII string.  If mode == DTOSTR_STANDARD and precision == 0 it's
+ * equivalent to ToString() as specified by ECMA-262-5 section 9.8.1, but it
+ * doesn't handle integers specially so should be avoided in that case (that's
+ * why js::NumberToCString() is better).
+ *
+ * The result is held somewhere in buffer, but not necessarily at the
+ * beginning.  The size of buffer is given in bufferSize, and must be at least
+ * as large as given by the above macros.
+ *
+ * Return nullptr if out of memory.
+ */
+char* js_dtostr(DtoaState* state, char* buffer, size_t bufferSize,
+                JSDToStrMode mode, int precision, double dval);
+
+/*
+ * DO NOT USE THIS FUNCTION IF YOU CAN AVOID IT.  js::NumberToCString() is a
+ * better function to use.
+ *
+ * Convert d to a string in the given base.  The integral part of d will be
+ * printed exactly in that base, regardless of how large it is, because there
+ * is no exponential notation for non-base-ten numbers.  The fractional part
+ * will be rounded to as few digits as possible while still preserving the
+ * round-trip property (analogous to that of printing decimal numbers).  In
+ * other words, if one were to read the resulting string in via a hypothetical
+ * base-number-reading routine that rounds to the nearest IEEE double (and to
+ * an even significand if there are two equally near doubles), then the result
+ * would equal d (except for -0.0, which converts to "0", and NaN, which is
+ * not equal to itself).
+ *
+ * Return nullptr if out of memory.  If the result is not nullptr, it must be
+ * released via js_free().
+ */
+char* js_dtobasestr(DtoaState* state, int base, double d);
+
+#endif /* util_DoubleToString_h */